Horizontal osteotomy implant, and methods of using the same

ABSTRACT

Various embodiments of craniofacial implants, surgical instruments, and techniques are described to provide improved surgical results.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation application and claimspriority to and the benefit of U.S. patent application Ser. No.13/532,283, filed on Jun. 25, 2012, now U.S. Pat. No. 9,895,211, titled“Craniofacial Implant Registration Features and Methods,” which is acontinuation-in-part of U.S. patent application Ser. No. 12/342,762,filed on Dec. 23, 2008, titled “Craniofacial Surgery Implant Systems andMethods,” which claims the benefit of each of the following threeprovisional U.S. patent applications: U.S. Provisional PatentApplication No. 61/018,943, filed Jan. 4, 2008, titled “Multi-ComponentCraniofacial Surgery Implant Systems and Methods;” U.S. ProvisionalPatent Application No. 61/018,948, filed Jan. 4, 2008, titled“Craniofacial Implant Registration Features and Methods;” and U.S.Provisional Patent Application No. 61/018,952, filed Jan. 4, 2008,titled “Craniofacial Implant Surgical Instruments and Methods.” Thesubject matter of each of the above identified patent applications ishereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The invention relates to surgical implants and more specifically tocraniofacial implant systems and associated surgical methods employingmultiple mating components and registration features on the implants.The invention further relates to surgical instruments and morespecifically to craniofacial implant surgical instruments and associatedsurgical methods.

BACKGROUND

Craniofacial surgery is generally performed to treat congenitaldeformities of the face and facial skeleton, to treat traumatic injury,or to address cosmetic or aesthetic concerns of the patient. Skilledsurgeons can enhance or reconstruct the facial skeleton usingbiocompatible implants that are disposed beneath the facial musculatureand applied to or attached to the facial skeleton (typically using screwfasteners). For example, craniofacial surgery and biomaterials can beused to create new facial skeletal contours. See, for example, ATLAS OFFACIAL IMPLANTS (Elsevier, 2007) by Michael J. Yaremchuk, MD, thedisclosure of which is incorporated herein by reference in its entirety.Unlike the use of injected liquid materials, that are meant to inflatethe soft tissue envelope, the use of solid facial implants can mimic thefacial appearance obtained with more extensive facial skeletal surgeriesthat require cutting and repositioning of facial bone. The facialimplants are typically provided in a limited number of basic shapes,that can be carved and shaped by the surgeon at the time of implant.

Facial implants are conventionally made from silicone rubber or sinteredporous plastics (such as polyethylene) that are molded intopredetermined shapes, depending on the area of the face to be treated.See, for example, U.S. Pat. No. 6,551,608, the disclosure of which isincorporated herein by reference in its entirety. For each area, afamily of implants of varying size and similar contour are oftenprovided. This is required, so that the facial implants can be readilycustomized to suit both the underlying skeletal contours and theoverlying facial tissue, in order to give the desired final appearance,without excessive sculpting of the implant by the surgeon during theimplant procedure.

Problems can exist, however, due to the relatively large size of some ofthe implants (e.g., requiring more extensive surgical access to the areato be augmented) and/or the amount of customization and associated timerequired, due to the limited selection of implants in each family. Ingeneral, temporary size implants are often used intraoperatively todetermine which implant shape might be appropriate, which requires alarge inventory of implants to be available to the surgeon. Implantswhich are not optimal for the specific needs of the patient can sometimebe used. Implants of different sizes must be custom carved and, inextreme cases, stacked and joined together by sutures if standardimplants are not ideal for specific clinical situations. Alternatively,a shim can be custom cut and inserted underneath the implant and affixedthereto by protuberances and adhesive, as described in U.S. Pat. No.5,514,179, the disclosure of which is incorporated herein by referencein its entirely. Current techniques can be inefficient and imprecise,and intraoperative constructs might be unstable in shape, leading tounpredictable outcomes. Further, the outcome can be less than ideal whenthe surgeon commits to opening an implant that, after placement, is lessthan ideal in projection.

The precise positioning of facial implants by the surgeon during theimplant procedure is often difficult and time consuming, due to limitedexposure of the areas to be augmented. Craniofacial implants aretypically placed through remote access incisions to avoid visiblescarring on the overlying soft tissue envelope and creation of suturelines directly over the implant which can predispose to wound breakdown,implant exposure and hence, surgical failure. Accurate implant placementis especially difficult when attempting to place a pair of implantssymmetrically. For example, symmetric placement of facial implants canbe problematic due to the complex three-dimension surface of the facialskeleton and limited surgical exposure.

In addition, placement of facial implants requires exposure (i.e.,removal of overlying attached soft tissues) of the skeletal area to beaugmented. Further, the implant needs to be held in proper positionwhile it is being secured to the underlying bone, typically with screws.Available conventional clamps (e.g., tissue forceps, bone reductionforceps, towel clips, etc.) do not provide stable purchase of theimplant and bone, due to their purchase end design, the dimensions ofthe purchasing end, and the configuration and orientation of thepurchasing end. Inadvertent movement of the implant while it is beingsecured can result in implant malposition and, if recognizedintraoperatively, the need to remove and reposition the implant.

SUMMARY

In one aspect, the present invention relates to craniofacial implantsincluding a base implant and an optional onlay component that iscontoured to the surface of the base implant allowing the overallprojection of the implant to be adjustable.

In one embodiment, the craniofacial implant includes a base implanthaving an inner contoured surface adapted to conform to a boneystructure and an outer contoured surface adapted to underlie softtissue. The craniofacial implant also includes an optional onlaycomponent having an inner contoured surface adapted to conform to atleast a portion of the outer contoured surface of the base implant andan outer contoured surface adapted to underlie soft tissue, to adjust anoverall projection of the implant. The craniofacial implant may includea means to attach the onlay component to the base implant. The means toattach the onlay component to the base implant can be a press fit,connecting tabs, a locking mechanism, or a registration feature. Thebase block and onlay component can include a biocompatible alloplasticmaterial.

In another aspect, the invention relates to a craniofacial implant thatincludes a pair of substantially mirror image implant components and anoptional central segment to adjust the overall dimension of the implant.The craniofacial implant can include a pair of substantially mirrorimage implant components and an optional central segment adapted to bedisposed therebetween and connected thereto, where the optional centralsegment can be selected from a group of segments having differentdimensions in order to adjust the overall dimension of the implant. Thecraniofacial implant can include a means to attach the central segmentto the implant components. The means to attach the central segment tothe implant components can be a removable bar.

In another aspect, the invention relates to an adjustable elongationblock implant including a base implant block having a substantiallyplanar surface to conform to a surgically cut boney structure and anouter substantially planar opposed surface adapted to conform to anoptional onlay block component and a mating surgically cut boneystructure. The adjustable elongation block also includes an optionalonlay block component having an inner substantially planar surfaceadapted to conform to the outer surface of the base implant block and anouter substantially planar opposed surface adapted to conform to atleast one of an optional second onlay block component and a surgicallycut boney structure, to fill a void formed by an osteotomy. The baseblock can be up to about 5 mm in height. The onlay component can be upto about 3 mm in height.

According to another aspect, the present invention relates to aninfraorbital rim implant including a medial rim implant portion and alateral malar implant portion that is selected from a group of at leasttwo malar implants having at least one different dimension, to adjust anoverall dimension of the implant. The infraorbital rim implant caninclude a means to attach the medial rim implant portion to the selectedlateral malar implant portion. The means to attach the medial rimimplant portion to the selected lateral malar implant portion can be aconnecting extension bar. The infraorbital rim implant can be providedin a kit including a medial rim implant portion, at least two lateralmalar implant portions having at least one different dimension, and aconnecting extension bar.

In another aspect, the invention relates to craniofacial implantsincluding an inner contoured surface adapted to conform to boneystructure and an outer contoured surface adapted to underlie softtissue, and a flange disposed along and extending from at least aportion of an edge thereof. The flange is adapted to abut a landmarkfeature of the boney structure, to position initially the implant alongat least one dimension. The craniofacial implant can be designed toaugment periorbital, midface and mandible surfaces (e.g. infraorbitalrim implants, mandible implants, and paranasal implants). The flange canbe positioned to abut the landmark feature selected from the groupconsisting of a lateral aspect of an orbital floor or wall, an aspect ofthe zygomatic arch, an inferior border of a mandible body or chin, aposterior border of a mandible ramus, and a pyriform aperture. Whenincluded on a mandible implant, the flange can be configured to allowaccurate and stable placement with minimal manipulation and disruptionof the pterygomasseteric sling.

Another aspect of the invention relates to a horizontal or a sagittalosteotomy implant including a flat surface adapted to lay on an anteriorface of each of a pair of relatively repositioned bones and apositioning ledge adapted to wrap around an inferior border of each ofthese bones to restore or create a continuous lower border.

Yet another aspect of the invention relates to a cranial implantcomprising a cranial body portion adapted to substantially fill acranial defect and a cranial thin edge portion of a periphery thereofthat is adapted to receive fasteners to attach the implant to thecranium. The periphery of the cranial thin edge portion can includeopenings, for instance through holes, that are configured to receive thefasteners to attach the implant to the cranium. In one embodiment, thethrough holes can be predrilled prior to insertion of the implant. Thefasteners can be chosen based on their length. In one embodiment a CTscan can be used to determine a thickness of the cranium that theimplant is being attached to. The fastener can then be selected based onthe thickness of the cranium such that the insertion of the fastenerdoes not increase the implant profile. The thin edge portion can includea taper. The taper can be from about 1.5 mm to less than 1 mm. Thecranial implant may further include an intracranial inner cup having aconvex surface adapted to a brain and an edge portion along at least aportion of a periphery thereof adapted to receive therethroughfasteners. The intracranial inner cup can be adapted to attach to atleast one of the cranial body portion and the cranial thin edge portion,or the cranial body portion.

Still another aspect of the invention relates to surgical instrumentsfor manipulating a craniofacial implant including a pair of pivotingjaws connected to a respective pair of finger grips, where each jawincludes spaced lobes to provide contact and preclude substantiallyrelative movement of a craniofacial implant disposed therebetween. Thesurgical instrument also includes a locking mechanism disposed betweenthe finer grips to retain the finger grips in at least one predeterminedrelative spacing corresponding to a nominal jaw opening. The pivotingjaw can include a pair of spaced lobes or three spaced lobes. Thelocking mechanism can include a ratchet system. The nominal jaw openingcan have a value in the range of about 1 mm to about 10 mm when thelocking mechanism is engaged. The jaws can be adapted to grasp acraniofacial implant therebetween. The nominal jaw opening can have avalue in a range of about 10 mm to about 50 mm when the lockingmechanism is engaged. The jaws can be adapted to clamp a craniofacialimplant to bone. The pivoting jaws can be adapted to open a distance ofup to about 4 mm. The distance from the lobes to the pivoting point canbe up to about 70 mm. The overall instrument length can be up to about140 mm. The pivoting jaws can be adapted to pen a distance of up toabout 20 mm. The distance from the lobes to the pivoting point can be upto about 60 mm. The overall instrument length can be up to about 100 mm.

The invention also relates to a facial implant instrumentation systemincluding various components, such as a straight periosteal elevator, acurved periosteal elevator, a cutting board with a grid system, at leastone surgical instrument described above, a 1.5 mm hand drill, a sterilebattery powered micro drill system allowing for a sleeve system forplacement of non-sterile batteries into the battery powered micro drill,a 2.0 mm selection of screws, a screw driver, a suction drain withtrocar, and an evacuation patty in various combinations. The facialimplant instrumentation system includes a selection of screws, a screwdriver, at least one surgical instrument described above, and at leastone sterile batter powered micro drill and an evacuation patty.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of various aspects and embodiments of theinvention can be better understood with reference to the schematicdrawings described below, and the claims. The drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the drawings, likenumerals are used to indicate like parts throughout the various views.In the drawings:

FIG. 1A is a schematic cross-sectional view of an adjustable sizecraniofacial implant in accordance with one embodiment of the invention;

FIG. 1B is a lateral view of the adjustable size craniofacial implant ofFIG. 1A;

FIG. 1C is a front oblique cross-sectional view of the adjustable sizecraniofacial implant of FIG. 1A;

FIG. 2A is a medial cross-sectional view of an adjustable mandible chinimplant in accordance with one embodiment of the invention;

FIG. 2B is a frontal view of the adjustable mandible chin implant ofFIG. 2A;

FIG. 3A is a top view of a craniofacial implant including a pair ofmirror image base implant components and an optional central basesegment in accordance with one embodiment of the invention;

FIG. 3B is a frontal view of the craniofacial implant of FIG. 3A;

FIG. 4A is a top cross-sectional view of an adjustable elongation blockimplant in accordance with one embodiment of the invention;

FIG. 4B is a cross-sectional side view of the adjustable elongationblock implant of FIG. 4A;

FIG. 4C is a frontal view of the adjustable elongation block implant ofFIG. 4A;

FIG. 5A is a frontal view of an infraorbital rim implant in accordancewith one embodiment of the invention;

FIG. 5B is a frontal view of the infraorbital rim implant of FIG. 5Awith a different size lateral malar implant portion;

FIG. 5C is an exploded view of the infraorbital rim implant of FIG. 5A;

FIG. 5D is a lateral end view of a portion of the infraorbital rimimplant of FIG. 5A;

FIG. 5E is a cross-sectional view of a portion of the infraorbital rimimplant of FIG. 5A;

FIG. 6A is a frontal view of an infraorbital rim implant with a flangein accordance with one embodiment of the invention;

FIG. 6B is a top view of the infraorbital rim implant of FIG. 6A;

FIG. 6C is a lateral cross-sectional view of the infraorbital rimimplant of FIG. 6A;

FIG. 7A is a side view of a mandible implant with flanges in accordancewith one embodiment of the invention;

FIG. 7B is a lateral view of the mandible implant of FIG. 7A;

FIG. 7C is a medial view of the mandible implant of FIG. 7A;

FIG. 8A is a lateral view of a paranasal implant with flanges inaccordance with one embodiment of the invention;

FIG. 8B is a medial view of the paranasal implant of FIG. 8A;

FIG. 8C is an anterior-lateral oblique view of the paranasal implant ofFIG. 8A;

FIG. 9 is a lateral perspective view of a horizontal osteotomy implantin accordance with one embodiment of the invention;

FIG. 10A is a depiction of a cranial implant in accordance with oneembodiment of the invention;

FIG. 10B is a depiction of a cranial implant in accordance with anotherembodiment;

FIG. 11A is a cross-sectional view of a cranial implant in accordancewith one embodiment of the invention;

FIG. 11B is a cross-sectional view of the cranial implant of FIG. 11Adenoting dead space;

FIG. 11C is a cross-sectional view of a cranial inner cup implantfilling the dead space of FIG. 11B;

FIG. 11D is a cross-sectional view of the cranial implant of FIG. 11Bwith the cranial inner cup implant of FIG. 11C;

FIG. 12A is a top perspective view of an implant positioning forceps inaccordance with one embodiment of the invention;

FIG. 12B is a side view of the implant positioning forceps of FIG. 12A;

FIG. 13A is a top perspective view of an implant positioning clamp inaccordance with one embodiment of the invention;

FIG. 13B is a side view of the implant positioning clamp of FIG. 13A;

FIG. 14A is a top view of an implant positioning clamp in accordancewith one embodiment of the invention having multiple lobes;

FIG. 14B is a side view of the implant of FIG. 14A;

FIG. 15 is a depiction of a facial implant instrumentation system inaccordance with one embodiment of the invention;

FIG. 16 is a schematic plan view of an evacuation patty in the system ofFIG. 15 in accordance with one embodiment of the invention;

FIG. 17A is a frontal view of a mandible implant according to anotherembodiment in an unassembled configuration, the mandible implantincluding a first and second body portions and a joining elementconfigured to attach to the first and second body portions;

FIG. 17B is a frontal view of the mandible implant illustrated in FIG.17A in an assembled configuration, the mandible implant including theconnecting bar shown in dotted lines positioned within the pair of baseimplant components;

FIG. 17C is a perspective view of the mandible implant according to FIG.17A in the assembled configuration;

FIG. 17D is a rear view of the mandible implant illustrated in FIG. 17A;

FIG. 17E is an end elevation view of the base implant componentsillustrated in FIG. 17A;

FIG. 17F is an end elevation view of the base implant componentsillustrated in FIG. 17A, but constructed in accordance with analternative embodiment;

FIG. 17G is a perspective view of an end of the first body portion ofthe mandible implant illustrated in FIG. 1, but constructed inaccordance with an alternative embodiment showing the joining elementintegral with one of the first and second body portions;

FIG. 18A is a perspective view of a malar implant according to oneembodiment;

FIG. 18B is a perspective view of a malar implant according to anotherembodiment;

FIG. 18C is a top view of the malar implant illustrated in FIG. 18A;

FIG. 18D is a bottom view of the malar implant illustrated in FIG. 18A.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

According to various embodiments of this invention, implants can be madein multiple mating pieces to reduce the inventory of implants required,while providing a high level of customization with limited sculpting orcustom shimming by the surgeon during the implant procedure. Whileporous polyethylene material may be used, the invention is not limitedin this regard and any suitable biocompatible material may be employed(e.g., rigid or flexible, porous or nonporous, polymer or nonpolymer,etc.). The implants of the present invention may be provided in kit formwith or without fasteners and/or conventional or specialized surgicalinstruments described herein.

A first embodiment, an example of which is shown in FIG. 1, providesimplants with adjustable projection. A two or more piece layeredconfiguration provides controlled variability in the amount ofaugmentation provided by a single implant. In general, this embodimentrelates to a craniofacial implant 10 including a base implant 12 havingan inner base contoured surface 14 adapted to conform to a boneystructure and an outer base contoured surface 16 adapted to underliesoft tissue. The craniofacial implant 10 further includes an optionalonlay component 18 having an inner onlay contoured surface 20 adapted toconform to at least a portion of the outer base contoured surface 16 andan outer onlay contoured surface 22 adapted to underlie soft tissue, toadjust an overall projection of the implant. The craniofacial implant 10further includes a means 19 to attach the onlay component 18 to the baseimplant 12.

In general, the craniofacial implant 10 consists of at least two pieces.The base implant 12 may be of variable shape and dimensions appropriateto augment the skeletal area of perceived deficiency. A second onlaycomponent 18 mimics the outer shape of the base implant 12. Theposterior contoured surface 20 of the onlay component 18 is congruentwith the mating contoured undersurface 16 of the base implant 12. Theonlay component 18 can be attached to the base implant by a press fit,connecting tabs, sutures, or other registration and interlock featuresknown in the art. Plugs or other suitable fillers can be used to conformexposed depressions in the outermost contoured surface base implant 12or only component 18, as necessary. Biocompatible adhesives may be usedalone or in combination with the mechanical attachment schemes. Thesurgeon can use either the base implant 12 or the base implant 12 andthe onlay component 18 together, as appropriate. Each optional third andsubsequent onlay component mimics the outer shape of the underlyingimplant piece.

This embodiment of the invention allows for selectability in the amountof augmentation provided by a single implant, which can be useful incases of facial asymmetry. The selectability is also useful when thesurgeon is unsure initially as to the appropriate amount ofaugmentation. The implant with and without its onlay component can beevaluated intraoperatively. Thus, a single implant provides options inthe amount of augmentation and decreases inventory requirements for thesurgeon, operating facility, and implant manufacturer.

In another embodiment, an adjustable size mandible chin implant 23 (seeFIG. 2A-2B) or an adjustable chin implant 27 can be provided (see FIG.3A-3B). The configuration of the mandible base implant 24 for themandible angle may be such that it provides up to about 6 mm or more oflateral augmentation and its optional mandible onlay component 26provides up to about an additional 4 mm or more. Similarly, theadjustable chin implant 27 can provide up to about 5 mm or moreprojection base implant, with an optional mandible onlay component 26having an additional up to about 3 mm or more projection. Additionally,due to the size of the adjustable chin implant 27, it can be made in twohalves, to facilitate insertion with minimal incision size. Similaronlay components (in any number of layers) can be configured for malar,chin, and nasal dorsum implant regions.

Moreover, the adjustable chin implant 27 can optionally be configured asa three segment implant, designed to augment the contours of the chin.This embodiment of the invention, alone or in combination with theadjustable projection feature, relates to a craniofacial implantincluding a pair of substantially mirror image base implant components28 and an optional central base segment 30 adapted to be disposedtherebetween and connected thereto, the optional central base segment 30selected from a group of segments having at least one differentdimension, to adjust an overall dimension of the implant. The adjustablechin implant 27 further comprises means to attach the central segment tothe implant components.

Conventional chin implants consist of a single piece of material ofcertain dimensions or two pieces joined at the center. The inclinationof the lateral limbs of the implant often do not mimic the inclinationof the inferior border of the mandible resulting in failure of theimplant to appropriately augment the inferior border. Moreover, a fixedcentral width may be inappropriate for a particular patient.

Mirror image base implant components 28 of this embodiment of theinvention allow the inferior border of the implant to be congruent withthe inferior border of the mandible, and the central base segment 30allows flexibility in control of the width and, therefore, shape of thechin. Thus, right and left limbs allow the inferior border of theimplant to be congruent with the inferior border of any mandible. Thisadvantageous feature of this embodiment of the invention is not possiblewith standard one piece implants. The central base segment 30, which canbe contoured and sized to any width, allows adjustment of the width ofthe chin. Removable bars 32 or other structures can be used to connectthe segments of the implant. The bars 32 fit into slots in each segmentof the adjustable chin implant 27. The bars 32 can be attached to themirror image base implant components 28 by a press fit, connecting tabs,sutures, or other registration and interlock features. The bars 32 may,alternatively, be integrally formed with either the central base segment30 or with the mirror image base implant components 28. Biocompatibleadhesives may be used alone or in combination with the mechanicalattachment schemes.

The adjustable chin implant 27 allows greater clinical application of asingle implant design. For example, a petite female requiring 5 mm ofsagittal projection may be best served with a 5 mm adjustable chinimplant 27 without a central base segment 30; whereas, a male requiring5 mm of sagittal projection may be best served with a 5 mm adjustablechin implant 27 with half of the central base segment 30. Alternatively,a male requiring 5 mm of sagittal projection and a square chin may bebest served with a 5 mm adjustable chin implant 27 with the entirecentral base segment 30. The three piece design provides controlledvariability in the amount of central width provided by a single implant.Thus, the single adjustable chin implant 27 provides options in theamount of augmentation and decreases inventory requirements for thesurgeon, operating facility, and implant manufacturer.

Another embodiment of the invention provides an adjustable elongationblock implant 34, configured to fill the space resulting from a chinosteotomy after vertical or sagittal advancement. The adjustableelongation block 34 can be used to correct deformities or to restore theoriginal contour of the underlying bony structure. In general, thisembodiment of the invention relates to a chin osteotomy implantincluding a base elongation implant block 36 having an innersubstantially planar surface adapted to conform to a surgically cutboney structure and an outer substantially planar opposed surfaceadapted to conform to at least one of an optional onlay elongation blockcomponent 38 and a mating surgically cut boney structure, and theoptional onlay elongation block component 38 having an innersubstantially planar surface adapted to conform to the outer surface ofthe base elongation implant block 36 and an outer substantially planaropposed surface adapted to conform to at least one of an optional secondonlay elongation block component 40 and a surgically cut boneystructure, to fill a void formed by osteotomy. The implant furtherincludes means to attach the optional onlay elongation block component38 to the base elongation implant block 36. One example of thisembodiment is depicted in FIGS. 4A-4C.

More specifically, a horizontal osteotomy performed to verticallyelongate the mandible typically leaves a gap between the mandible properand the mobilized chin segment. This gap makes the lowered chin positionunstable. The chin osteotomy adjustable elongation block implant 34 isadapted to fill this space. The adjustable elongation block implant 34can be made of any strong material, such as a biocompatible alloplasticmaterial. In this embodiment the adjustable elongation block implant 34consists of a base elongation implant block 36 up to about 5 mm inheight or more. Onlay elongation block components 38 of up to about 3 mmor more in height can be press fit to allow adjustment of the chinheight. The adjustable elongation block implant 34 allows the spacebetween the bone segments to be precisely controlled and maintained atthese intervals. A final elongation block component 40 can cap theadjustable elongation block implant 34. The bone segments are thenimmobilized with the surgeon's desired fixation technique (e.g., platesand screws). The adjustable elongation block implant 34 is suitablewhenever a surgeon performs a vertical elongation of the chin afterhorizontal osteotomy. Naturally, the onlay elongation block components38 can be of the same or different heights and need not be rectangularin shape.

The adjustable elongation block implant 34 allows precise maintenance ofthe desired distance between the osteotomized segment and the mandibleproper and hence, chin height. It eliminates the potential for anyasymmetries at either end of the osteotomy, by filling the resultantvoid after osteotomy and elongation resulting instability of themovement. The adjustable elongation block implant 34 also lessens spaceavailable for hematoma accumulation and eliminates the need for bonegrafts (with accompanied donor site morbidity) or use of bonesubstitutes that may not provide sufficient rigidity. The need to createspacers, custom-carved from for example, large polyethylene blocks, isalso eliminated. The use of the elongation block implant 34 provides formore efficient, precise and predictable surgery. Further, the adjustablenature of the elongation block implant 34 allows intraoperativeadjustment without penalty of opening another implant.

Another embodiment of the invention depicted in FIGS. 5A-5E, relates toan infraorbital rim implant 42, typically used to treat congenital orpost-traumatic upper midface concavity, relative upper midfacedeficiency after Lefort I lower maxillary advancement, as well assenescent upper midface deficiency as part of facial rejuvenationprocedures. The complex configuration of the infraorbital rim andlimited surgical access make placement of a conventional implant tediousand adaption to the underlying skeleton difficult. This embodiment ofthe infraorbital rim implant 42 includes a medial rim implant portion 44and a lateral malar implant portion 46 selected from a group of at leasttwo malar implants having at least one different dimension, to adjust anoverall dimension of the implant. The infraorbital rim implant 42further includes means to attach the medial rim implant portion 44 tothe selected lateral malar implant portion 46.

In one embodiment, the means of attaching the lateral malar implantportion 46 and medial rim implant portion 44 is a connecting extensionbar 48 joining the two halves of the infraorbital rim implant 42. Theextension bar allows the infraorbital rim implant 42 to be placed as twoseparate halves. The connecting extension bar 48 also gives theinfraorbital rim implant 42 flexibility, effectively allowing theimplant to hinge to better conform to the underlying skeleton. Thelateral malar implant portion 46 can include a larger malar option piece46′ similar to lateral malar implant portion 46 to allow it to covermore of the malar aspect in addition to the medial rim implant portion44. See FIG. 5B. As with the adjustable chin implant 27 described above,the connecting extension bar 48 fits into slots in each half. Theconnecting extension bar 48 can be attached to each half by a press fit,connecting tabs, sutures, or other registration and interlock featuresknown in the art. The connecting extension bar 48 may, alternatively, beintegrally formed with either half, for example, with titanium wire ormesh. Biocompatible adhesives may be used alone or in combination withthe mechanical attachment schemes. This aspect of the invention alsopresents an implant kit including a consistent medial rim implantportion 44 and two or more possible lateral malar implant portions 46,along with the connecting extension bar 48.

The infraorbital rim implant 42 design facilitates implant placement andpositioning. It allows the infraorbital rim implant 42 to fit flush onthe underlying skeleton and the adjacent anterior malar area to beaugmented in a seamless, coordinated way. This improvement eliminatesthe need to modify existing implants, for example by cutting into piecesto allow placement and conformability. This improvement also eliminatesthe need to overlay a separate malar implant over the rim implant, ifthe malar area also requires augmentation. This improvement preventsinaccurate reassembly of segmented implants, and difficulties associatedwith placement of secondary malar implants over primary rim implants.

According to another aspect of the present invention, the implants maycontain registration features that are provided to align with or abutspecific features of the facial skeleton. In one embodiment, theinvention relates to craniofacial implants having an inner contouredsurface adapted to conform to boney structure and an outer contouredsurface adapted to underlie soft tissue, and a flange 50 disposed alongand extending from at least a portion of an edge thereof, the flangeadapted to abut a landmark feature of the boney structure, to positioninitially the implant along at least one dimension. In certainembodiments, the implant can be an infraorbital rim implant 42 (seeFIGS. 6A-6C), a mandible chin implant 23 (see FIGS. 7A-7C), or aparanasal implant 52 (see FIG. 8A-8C). For such embodiments, the flange50 is positioned to abut the following respective landmark features: alateral aspect of an orbital floor, an inferior border of a mandiblebody and a posterior border of a mandible ramus, and a pyriformaperture.

For example, according to a first embodiment of the invention, theplacement of small flanges 50 on the posterior surface of certain facialimplants (e.g., infraorbital rim, mandible and paranasal implants in theattached depictions) allows accurate positioning relative to fixedanatomic landmarks. This allows accurate, symmetric three-dimensionalplacement of these implants.

For such implants, the flange 50 on the infraorbital rim implant abutsthe lateral aspect of the orbital floor. The series of flanges on themandible implant abut the inferior border of the mandible body and theposterior border of the mandible ramus to provide both vertical andtransverse location registration. The flanges 50 on the lateral andmedial aspects of the paranasal implants abut the pyriform aperture.

The flanges 50 or projections assure accurate, symmetric implantplacement and avoid reliance on visual cues to position the implants,that can lead to inaccurate positioning. The flanges 50 result in moreefficient, precise and predictable outcomes.

Another embodiment of the invention relates to an implant that can beused with patients undergoing a horizontal osteotomy of the mandiblethat is being performed to change the location of the chin point withattached soft tissues. In this procedure, the chin point may be movedvertically sagittally, transversely, or in a combination of thesedirections. The osteotomy (i.e., the cut in the bone) creates adiscontinuity along the inferior border of the mandible which isexaggerated by the movement of the chin segment. Depending on the amountof movement and the thickness of the overlying soft tissues, theresultant gap between the stationary mandible and its mobilized chinpoint may be visible and deforming. The horizontal osteotomy implant 54,depicted in FIG. 9, is adapted to bridge the gap between the two bonesegments and restore a smooth mandibular border. In one embodiment, theimplant 54 is configured to restore continuity in the mandible borderafter a sagittal osteotomy of the mandible.

The horizontal osteotomy implant 54 can be placed at the time that thehorizontal osteotomy is performed or at a later time. Bone at eitherside of the osteotomy are exposed and freed of their attached softtissues to allow placement of the implant. The horizontal osteotomyimplant 54 has a flat surface that lies on the anterior face of eachbone. It has a positioning ledge 56 (e.g., a 1 mm ledge) that wrapsaround the inferior border of each bone. The horizontal osteotomyimplant 54 is adapted to bridge the gap between the two bone segmentsand restore a smooth mandible border. By bridging the osteotomy gap, thecontour discontinuity caused by the separation of the two bones issmoothly transitioned and any otherwise discernible appearance thereofis eliminated. A precise and stable, regular border of the mandible isrestored, since the implant is tailored to fit the precise anatomicneeds of the situation and can be immobilized with screws, if necessary.

Use of the horizontal osteotomy implant 54 avoids the need to injectsubstances (e.g., hydroxyapatite, fat, and various filler materials)percutaneously into these defects, to attempt to soften the transitionbetween the relocated chin point and mandible. Since the horizontalosteotomy implant 54 is placed under direct vision and can beimmobilized with screws, an aesthetically appealing result can beensured.

Cranial vault implants made through computer aided design and computeraided manufacturing (CAD/CAM) are traditionally made to fill exactly askeletal defect in the cranial vault. Its position is stabilized withplates and screws. Prominent fixation hardware may erode through theoverlying scalp closure leading to implant exposure and surgicalfailure. Another cause of surgical failure occurs in situations whenthere is space between the inner surface of the implant and the brain.Such a space (termed dead space) predispose to fluid accumulation andpossible infection. Two versions of a cranial vault implant aredescribed according to various embodiments of the invention to avoidthese problems.

In general, FIG. 10 depicts one embodiment of a cranial implant 58 thatincludes a cranial body portion 60 adapted to fill substantially acranial defect and a cranial thin edge portion 62 along at least aportion of a periphery thereof. The cranial thin edge portion 62 isadapted to receive therethrough fasteners to attach the cranial implant58 to the cranium. In one embodiment, the cranial thin edge portion 62is a taper.

In the embodiment depicted in FIG. 10A and FIG. 11A, the cranial implant58 provides a location flange on a custom computer tomography generatedcranial implant 58 that is designed to not only fill the cranial defect,but also to have the cranial thin edge portion 62 extending over theadjacent intact skull. The periphery of the cranial thin edge portion 62can include openings, for instance through holes, that are configured toreceive fasteners to attach the cranial implant 58 to the cranium. Inone embodiment, the through holes can be predrilled prior to insertionof the implant. A computer topography scan can be used to determine athickness of the cranium and based on the thickness of the cranium,fasteners can be chosen with a length such that the insertion of thefastener does not increase the implant profile. In one embodiment, theextension from the cranial thin edge portion 62 allows the implant to befixed with lag screws, as opposed to higher profile plates and screws.Lag screws can be less prominent and less likely to erode through theoverlying scalp. The extension from the cranial thin edge portion 62also fills any gaps between the posterior surface of the scalp and anymismatch between the implant and the intact skull, that would otherwisebe subject to soft tissue instability. The cranial implant 58configuration allows the fixation hardware to be placed remote from theoverlying scalp incision. It also decreases the likelihood of implantexposure, by extending the implant beyond the cranial defect and theoverlying scalp incision, resulting in a more efficient, precise andpredictable outcome than existing methods.

In one embodiment, the cranial thin edge portion 62 can have athickness, tapering from up to about 1.5 mm or more to less than about 1mm and have a lateral or radial extent of up to about 1 to 5 mm or moredepending on the location of the scalp incision to the underlying areaof skull reconstruction.

Referring to FIG. 10B, in another embodiment the cranial implant 58 caninclude a body portion 60 that defines an outer surface 57; an opposedinner surface 59; and a side wall 61 that extends between the outersurface 57 and inner surface 59. The side wall 61 defines a shape or anouter periphery of the body portion 60, for instance circular. In oneembodiment the body portion 60 is configured such that the cranialimplant 58 fits within, for instance entirely within, the cranial defect63. As shown in the illustrated embodiment, the outer surface 57 doesnot extend beyond the outer surface of the cranium, and the side wall 61does not extend beyond a periphery of the cranial defect 63. Forexample, the embodiment shown in FIG. 10B does not contain a cranialthin edge portion 62 as shown in FIG. 10A. The body portion 60 canfurther define openings 65, for instance predrilled holes, which areconfigured to receive a fastener, for instance a bone screw, such thatwhen the cranial implant 58 has been secured to the cranium thefasteners are flush or countersunk with respect to the outer surface 57of the cranial implant 58. The openings 65 can be oriented obliquelysuch that the opening 65 extends into the body portion 60 at an angle,for instance a non-normal angle, with respect to the outer surface 57.The opening 65 can extend through the body portion 60 and exit the bodyportion 60 at the side wall 61 such that a fastener inserted into theopening 65 can be secured to the cranium as shown.

Another cranial implant 58 embodiment addresses situations where thereis an anticipated space (“dead space”) between the inner surface of theimplant and the brain (see FIGS. 11A-11D). In this instance a secondimplant piece is employed. An intracranial inner cup 64 can be designedusing magnetic resonance (MR) or computed tomography (CT) data to adaptits convex surface to the outer concave surface of the brain, thusfilling the dead space. Optional perforations in the floor of theimplant allow sutures to secure the dura to the outer surface of theimplant thus further eliminating potential for “dead space.” Theintracranial inner cup 64 can be shaped to allow it to be fastened withscrews to the intact edge of the skull vault. The cranial implant 58 isfashioned to restore the skull vault contour and can be adapted to fitwithin the perimeter edge of the intracranial inner cup 64. In certainclinical situations, both the intracranial inner cup 64 and the cranialimplant 58 could be fashioned into a single implant.

Another aspect of the invention relates to surgical instruments that aidin a more efficient and precise implant surgery. The surgeon often hasvery limited access to the skeletal area to be augmented. Due to theaesthetics involved in craniofacial surgery, placement of facialimplants often entails less exposure by incision than would otherwise bedesirable for surgical access. Once access is achieved, the implant isinserted and then must be positioned and adjusted until an optimallocation is achieved. Thereafter, the implant needs to be held in properposition while it is being secured to the underlying bone, typicallywith screws. All such access for insertion, positioning, holding, andattachment is limited, to minimize the disturbance and scarring of thepatient.

According to various embodiments of the invention, implant positioningforceps 80 and implant positioning clamps 82 (see FIGS. 13A-13B) areprovided to facilitate more efficient, precise, and predictable surgerythan heretofore has been achievable. In general, this aspect of oneembodiment of the invention relates to a surgical instrument formanipulating a craniofacial implant, the instrument 80 including a pairof pivoting jaws 72 connected to a respective pair of finger grips 74,wherein each jaw includes a pair of spaced lobes 76 to provide up tofour point contact and preclude substantially relative movement of acraniofacial implant disposed therebetween. A locking mechanism 78 isdisposed between the finger grips to retain the finger grips in at leastone predetermined relative spacing corresponding to a nominal jawopening 88. In various embodiments, the surgical instrument 70 has a thenominal jaw opening value in a range of up to about 1 mm to about 10 mmor more, when the locking mechanism is engaged. Such embodiments may beparticularly useful as implant positioning forceps 80, wherein the jawsare adapted to grasp solely a craniofacial implant therebetween. Invarious alternative embodiments, the surgical instrument has a nominaljaw opening value in a range of up to about 10 mm to about 50 mm ormore, when the locking mechanism 35 is engaged. Such embodiments may beparticularly useful as an implant positioning clamp 82, wherein the jawsare adapted to clamp a craniofacial implant to bone.

The implant positioning forceps 80 are configured and dimensioned tosecurely grasp facial implants during their placement or immobilizationwith screws. These implant positioning forceps 80 are especially usefulin the midface and upper face, where the implant cannot be clamped tothe bone (which is the preferred method in the mandible). The implantpositioning forceps 80 have pivoting jaws 72 that grasp the anteriorsurface of the implant at various regions, to hold the implant in theforceps. The pivoting jaws 72 can be non-specific, in that they need notbe designed to mate with a particular implant and therefore need nothave extended jaw surfaces that are designed to conform to the surfacesof a particular implant. The finger grips 74 and locking mechanism 78permit secure, stable holding of the implant and prevent implantmovement during the stabilization process.

Available conventional forceps do not open their jaws sufficiently tograsp securely most facial implants, nor do they maintain stablepurchase of the implant. The pivoting jaws 72 of the forceps 80 of oneembodiment of the invention have a jaw opening distance 88 of about 4mm, a pivot arm length 84 of about 70 mm, and an overall instrumentlength 86 of about 140 mm. The lobes 76 provide reliable retention,without structurally damaging the implant. Other dimensions arecontemplated.

In those procedures where the undersurface of the bone is accessible(e.g., the mandible), an implant positioning clamp 82 according to oneembodiment of the invention may be used, an example of which is shown inFIGS. 13A-13B. The implant positioning clamp 82 holds the implant in astable desired position relative to the bone (e.g., the mandible) sothat screws can be placed to permanently immobilize the implant. In oneembodiment, in which the implant is applied to the anterior surface ofthe mandible, one of the pivoting jaws 72 purchases the anterior face ofthe implant and the other jaw purchases the posterior surface of themandible. Accordingly, the pivoting jaws 72 of the clamp grasp theanterior surface of the implant and the undersurface of the bone towhich it is being secured. The pivoting jaws 72 can be non-specific, inthat they need not be designed to mate with a particular implant andtherefore need not have extended jaw surfaces that are designed toconform to the surfaces of a particular implant. Its finger grip 74 andlocking mechanism 78 prevent implant movement during the stabilizationprocess. The implant positioning clamp 82 configuration and dimensionsallow it to immobilize temporarily an implant to the surface of themandible so that drill holes can be made through the implant andunderlying bone in anticipation of fixing the implant to the mandiblewith screws. The pivoting jaws 72 of the implant positioning clamp 82 ofone embodiment of the invention have a jaw opening distance 88 of about20 mm, a pivot arm length 84 of about 60 mm, and an overall instrumentlength 86 of about 140 mm, as depicted. This technique affords stable,essentially hands-free immobilization of the implant during its securingto the facial skeleton.

Use of these implant positioning forceps 80 and implant positioningclamps 82 permit the implant to be readily positioned and held orimmobilized during the final screw stabilization process. The surgicalinstruments prevent misalignment of the drill holes in the implant andunderlying skeleton, which must be coaxial to allow screw purchase andproper implant immobilization. Movement of the implant during thefixation process with prior art techniques results in prolongedoperating times and can result in implant malposition. Use of thesurgical instruments avoids implant malposition, resulting in moreefficient, precise, and predictable surgery.

FIGS. 12A-12B and FIGS. 13A-13B depict a pair of twin lobed jaws;however, a single lobed jaw could be paired with a twin lobed jaw, toprovide three point contact with and retention of the implant, in eitherthe forceps or clamp configurations. At least three point contact isdesired, to constrain the implant from rotation when grasped with theforceps or when held in place with the clamp. Pivoting jaws 72 with morethan two lobes 76 are also contemplated. In one embodiment of such clamp82′, an example of which is depicted in FIGS. 14A-14B, one pivoting jaw72′ contains at least three lobes 76′ and the other pivoting jawcontains at least two lobes 76′. The lobes 76′ interdigitate whenclosed. This clamp 82′ can be useful in clamping a chin implant to apatient's chin. The jaw opening distance 88′ should be suitably sized toprovide effective clamping with the ratchet or other locking mechanism78′ engaged.

Further, as depicted, the orientation of the pivoting jaw 72 opening isperpendicular to the plane of the clamp 82 and is generally aligned withthe longitudinal axis of the clamp 82. Instruments with other pivotingjaw opening orientations, angularly offset jaws, curved sections betweenthe pivot and the jaws and/or finger grips, etc. are all contemplatedand considered to be within the scope of the invention. Still otherembodiments can include alternatives to finger grips (e.g., pistolgrips) or eliminate the grips altogether, having a tweezer configurationwith a spring loaded pivot or paired cantilevered arms joined at a pointremote from the jaws. The ratchet or other locking mechanism 78 couldthen be disposed on the jaw side of the pivot or joined section. Variousembodiments of the surgical instruments can be made of surgicalstainless steel or other suitable material, for reuse. Alternatively,the surgical instruments can be made of suitable polymers or compositematerials that may be sterilized and included in single-use surgicalkits, and disposed of once the surgical procedure has been completed.

Various aspects and embodiments of the present invention include afacial implant instrumentation system 90) to facilitate accurateplacement and stabilization of facial implants. An example of thisembodiment is depicted in the schematic of FIG. 15. Precise and stablepositioning of implants is fundamental to the success of craniofacialimplant surgery. In various embodiments the facial implantinstrumentation system 90 can include in various combinations some orall of the following components, including periosteal elevators,straight and curved, to develop subperiosteal pockets for implants. Thefacial implant instrumentation system 90 can include an implant cuttingboard to contour implant with a scalpel or a burr prior to implantation.The cutting board may include a grid system that allows for symmetriccontouring and accurate photographic documentation of the implants used.The facial implant instrumentation system 90 can include at least oneimplant positioning clamp 82 and/or implant positioning forceps 80 toimmobilize implants during screw fixation. The facial implantinstrumentation system 90 can include a 1.5 mm hand drill and a sterilebattery powered micro drill system, which has a sleeve system forplacement of non-sterile batteries into an otherwise sterile drillsystem. The facial implant instrumentation system 90 can include a 2.0mm or other sized selection of screws (e.g. 6 to 14 mm length), screwdrivers, a suction drain with trocar, and evacuation patty 92, oneembodiment of which is depicted in FIG. 16. The evacuation patty 92 canbe a cottonoid 94 that is embedded a perforated catheter 96 whose otherend is attached to a conventional suction source mechanism. Theevacuation patty 92, an example of which is depicted in FIG. 16, isadapted to gently remove fluids and smoke from the operative field.

As described hereinabove, surgery on the facial skeleton is usually madethrough remote incisions. As a result the surgical field for example,the deep orbit, is visible only to the surgeon. The evacuation of bloodor smoke from use of electrocautery becomes difficult. The evacuationpatty 92 removes these elements from the operative field without inputfrom an assistant or the operator. The evacuation patty 92 in oneembodiment consists of a neurosurgical cottonoid 94 of dimensions ofapproximately about 1×1.5 cm. Imbedded in its central aspect is aperforated end of a 19 gauge plastic catheter 96. The other end of thecatheter 96, which is approximately 35 cm long, is coupled to standardoperating room suction tubing 98 which, in turn is connected to asuction mechanism. Placement of the small cottonoid 94 after wetting inthe operative does not obscure visualization of the field. Suctionapplied to the wetted cottonoid 94 allows evacuation of fluids in thefield through capillary action. For an example of a device used tomaintain a clear field during microsurgical vessel anastomosis, seeZienowicz R J, Jupiter J B. Yaremchuk M J: A microsurgical suction mat.J Hand Surg., 19A, 519-520 (1994), the disclosure of which isincorporated herein in its entirety.

Referring to FIGS. 17A-17G, a mandible implant 100 (also known as a chinimplant) can include a first body portion 102, a second body portion 104and a joining element 106 that is configured to attach and secure thefirst and second body portions 102 and 104 together. The first andsecond body portions 102 and 104, respectively, can be symmetrical, forinstance, mirror images of each other, such that the first and secondbody portion 102 and 104, respectively, each contain similar shapes andfeatures. Therefore any description of the structure or elements of thefirst body portion 102 below can also be applicable to the second bodyportion 104, unless otherwise indicated. It should be appreciated thatthe first body portion 102 and the second body portion 104 may haveslight differences, such as the exact size and shape of the bodyportions 102 and 104 and the inclusion or positioning of variousstructure carried by one or both of the first and second body portions102 and 104, as described in more detail below.

The first body portion 102 defines a pair of opposed ends, such as afirst or proximal end that can be configured as an anterior base 114,and a second or distal end that can be configured as a posterior tip 112that is opposite and spaced from the anterior base 114 along a centralaxis 113 that can be shaped as desired so as to correspond to anunderlying boney structure. For instance, in accordance with theillustrated embodiment, the central axis 113 is curved. The first bodyportion 102 further defines a first surface such as an inner surface110, which is a bone-facing surface in accordance with the illustratedembodiment, and a second surface such as an outer surface 108 that isopposite and spaced from the inner surface 110 along a lateral or firstdirection 115 that is substantially perpendicular to the central axis113. The inner and outer surfaces 110 and 108 can extend between theposterior tip 112 and the anterior base 114, and in accordance with theillustrated embodiment extend, for instance continuously, from theposterior tip 112 to the anterior base 114. The first body portion 102can further define a first edge such as a superior edge 116 and a secondedge such as an inferior edge 118 that is opposite and spaced from thesuperior edge 116 along a transverse second direction 117 that issubstantially perpendicular to both the axis 113 and the firstdirection. The superior and inferior edges 116 and 118 can extendbetween the posterior tip 112 and the anterior base 114, and inaccordance with the illustrated embodiment extend, for instancecontinuously, from the posterior tip 112 to the anterior base 114. Thesuperior and inferior edges 116 and 118 can further extend between theinner and outer surfaces 110 and 108, and in accordance with theillustrated embodiment extend, for instance continuously, from the innersurface 110 to the outer surface 108. Accordingly, the outer surface 108and inner surface 110 can each extend substantially vertically from thesuperior edge 116 to the inferior edge 118 and substantially along thecentral axis 113 the posterior tip 112 to the anterior base 114.

The first body portion 102 can be tapered such that superior edge 116and the inferior edge 118 taper toward each other along a direction fromthe anterior base 114 toward the posterior tip 112. Furthermore, one orboth of the superior edge 116 or the inferior edge 118 can be feathered.For instance, one or both of the inner or outer surfaces 110 and 108 cantaper toward each other along the second direction 117 from the centralaxis 113 toward the superior edge 116, and one or both of the inner orouter surfaces 110 and 108 can taper toward each other along the seconddirection 117 from the central axis 113 toward the inferior edge 118. Inaccordance with one embodiment, one or both superior or inferior edges116 or 118 can abut the underlying bone once the mandible implant 100has been implanted to an underlying human mandible.

The first body portion 102 is shaped to correspond to that of theunderlying human mandible. For example, the inner surface 110 can definea contour having a concavity 119 such that when the inner surface 110 ispositioned adjacent to the underlying human mandible the inner surface110 mates flush with the mandible. The inner surface 110 beingconfigured to mate flush with the mandible can result in bettercongruence, for instance less gapping and more predictability ofaugmentation, between the inner surface 110 and the mandible. The outersurface 108 can also define a curvature 121 that is convex. In oneembodiment, when the underlying mandible is damaged or deformed, theouter surface 108 can be configured with a curvature 121 such that theouter surface 108 does not extend substantially parallel to acorresponding outer surface of the underlying mandible. The curvature121 can be configured to restore a normal mandible appearance, forinstance such that the mandible is symmetrical. In another embodiment,when the outer surface of the mandible is largely intact with only minordeformation, the outer surface 108 can be configured with a curvature121 such that the outer surface extends substantially parallel to acorresponding outer surface of the underlying mandible in order tominimize the change in shape or appearance of the patient's mandibleafter the mandible implant 100 has been implanted to the mandible.Additionally, the inferior edge 118 can be inclined along a directionfrom the anterior base 114 toward the posterior tip 112 so as to extendsubstantially parallel to a complementary inclination of an inferiorborder of a patient's mandible. The first portion 102 can furtherinclude a lip 129 positioned adjacent the inferior edge 118 with a shapecomplementary to that of the inferior border of the patient's mandible.

The first body portion 102 defines a height H1 that can be definedbetween the superior edge 116 and the inferior edge 118 along the seconddirection 117. It should be appreciated that the height H1 at the base114 can be as desired so as to accommodate a wide range of sizes andshapes of an underlying mandible. It may be desirable to provide themandible implant 100 having a first height H1 for a patient with alarge, square chin, and to provide the mandible implant 100 having asecond height H1 that is smaller than the first height H1 for a patienthaving a smaller chin. A mandible implant 100 that has a shape that isconfigured to correspond to that of an underlying mandible can lead to amore stable and aesthetically pleasing result after implantation. Itshould thus be appreciated that a kit can include a plurality ofmandible implants 100 of various shapes and sizes (for example withdifferent heights H1) sized to fit various sized mandibles.

The first body portion 102 can also include a registration feature thatis configured to align with or abut complementary landmark features ofthe facial skeleton. As shown, the registration feature can beconfigured as a flange 50 that extends out from the inner surface 110substantially along the first direction 115. For instance, the flange 50can extend from the inner surface 108 along a direction from the outersurface toward the inner surface. The flange 50 can define a first orsuperior surface such as an abutment surface 122, and an opposed secondor inferior surface such as an exterior surface 124 that is spaced fromthe abutment surface 122 along the second direction 117. The flange 50can define a height H2 that is defined between the abutment surface 122and the exterior surface 124 along the second direction 117. Theabutment surface 122 can be contoured to correspond to a complementarylandmark feature of the facial skeleton.

The flange 50 can be angularly offset with respect to the inner surface110 and substantially rigidly positioned such that the abutment surface122 of the flange 50 is configured to abut the complementary landmarkfeature of the underlying mandible so as to prevent movement of theimplant 100 relative to the underlying mandible in at least onedirection when the implant 100 is positioned against the underlyingmandible. For example, the abutment surface 122 can be configured toabut the inferior border of an underlying mandible so as to interferewith the underlying mandible when a force is applied to the implant 100along a superior direction, along the direction 117. Accordingly,movement of the implant 100 in the superior direction, along the seconddirection 117, is prevented when the implant 100 is positioned adjacentthe underlying mandible. It can further be said that the flange 50 canbe angularly offset to the inner surface 110 and positioned such thatthe abutment surface 122 is configured to abut a landmark feature of anunderlying mandible such that movement of the implant 100 in a directionparallel to the inner surface 110 is prevented when the inner surface110 is positioned adjacent the underlying mandible.

As shown, the flange 50 can extend out from the inner surface 110 at alocation adjacent the inferior edge 118. Alternatively, the flange 50can extend out from the inner surface 110 at any position along theheight H1 of the implant 100 from the inferior edge 118 to the superioredge 116 (including the inferior edge 118 and the superior edge 116). Inone embodiment, the flange 50 can extend substantially perpendicularfrom the inner surface 110 such that the flange 50 is positionedadjacent the inferior edge 118 of the first body portion 102 such thatflange 50 will abut the inferior border of the underlying mandible.Alternatively, the implant 100 can define any angle as desired betweenthe flange 50 and the inner surface 110. Furthermore, the flange 50 canbe positioned at any location on the inner surface 110 between thesuperior edge 116 and the inferior edge 118 such that the flange 50aligns with or abuts the complementary landmark feature of theunderlying facial skeleton. It should be appreciated in accordance withthe illustrated that the flange 50 can be devoid of bone fixation holesthat receive a bone fixation member, such as a nail or a screw, toattach the flange to the underlying mandible. It should be appreciated,however, in certain embodiments that the flange 50 can include bonefixation holes as desired.

The first body portion 102 can include a recess 120 that extends intothe anterior base 114 substantially along the central axis 113. Therecess 120 can be sized to receive the joining element 106. Forinstance, the recess 120 can be sized substantially equal to the joiningelement 106 such that the joining element 106 is press-fit into therecess 120 so as to attach the first and second body portions 102 and104. For instance, the joining element 106 can be positioned within therecess 120 at various depths along the central axis 113 such that thefirst body portion 102 and the second body portion 104 can be spacedapart along an adjustable distance. For instance, a variable sized gapcan extend between the anterior bases 114 of the first and second bodyportions 102 and 104 when the first and second body portions 102 and 104are attached to each other. For example, the joining element 106 can beinserted into the recess 120 of the first and second body portions 102and 104 to a first depth such that the anterior bases 114 of the firstand second body portions 102 and 104 abut each other, such that thevariable sized gap is zero. Alternatively, the joining element 106 canbe inserted into the recess 120 of the first and second body portions102 and 104 to a second depth less than the first depth such that theanterior base of the first and second body portions 102 and 104 areseparated by the gap along a distance greater than zero. Thisadjustability can provide for a number of different jaw widths to beaccommodated by the mandible implant 100.

In accordance with the illustrated embodiment, the joining element 106can be separate from one or both of the first and second body portions102 and 104. In accordance with one embodiment, joining element 106 canbe integral and monolithic with one of the first and second bodyportions 102 and 104 (see FIG. 17G), such that the other of the firstand second body portions 102 and 104 carries the complementary recess120 that is configured to receive the joining element 106. Thecomplementary recess 120 can be integral with the other of the first andsecond body portions 102 and 104 as illustrated, or can be defined by asecond member that is attached to the other of the first and second bodyportions 102 and 104.

Referring to FIGS. 18A-18D, a malar implant 140 can include a body 142and one or more registration features such as flange 50. The body 142defines an outer edge such as a peripheral edge 148. The body 142further defines a first surface such as an inner surface 146, which is abone facing surface in accordance with the illustrated embodiment, and asecond surface such as an outer surface 144 that is opposite and spacedfrom the inner surface 146 along a first direction 147. The inner andouter surfaces 146 and 144 can extend, for instance continuously, fromthe peripheral edge 148 at a first location to the peripheral edge at asecond location spaced apart from the first location. The body 140defines a shape that can be configured to correspond to that of a humanmalar bone (also referred to as the zygomatic bone or cheek). Forexample, the inner surface 146 can define a contour having a concavity155 such that when the inner surface 146 is positioned adjacent to anunderlying human malar the inner surface 146 mates flush with the malarbone. The outer surface 144 can also define a curvature 157 that isconvex so as to extend substantially parallel to a corresponding outersurface of the underlying malar bone in order to minimize the change inshape of the appearance of the patient's cheek after implantation of themalar implant 140 has been implanted to the malar. Additionally, theperipheral edge 148 can be configured to closely conform to adjacentunderlying bone structures, such as the zygomatic arch or the lateralinfraorbital rim, to minimize the change in shape of the appearance ofthe patient's cheek after implantation of the malar implant 140. Itshould appreciated that the shape of the body 142 defined by theperipheral edge 148 can be as desired so as to accommodate a wide rangeof sizes and shapes of an underlying malar.

The body 142 defines a width W1 that can be defined between the innerand outer surfaces 146 and 144 along the first direction 147. It may bedesirable to provide the malar implant 140 having a first width W1 at alocation roughly near a middle of the body 142 and a second width W1 ata location adjacent the peripheral edge 148 such that the body 142 istapered and the width W1 decreases closer to the peripheral edge 148 ofthe malar implant 140. In one embodiment, the peripheral edge 148 can befeathered such that the width W1 tapers down to the peripheral edge 148such that there is no visible border between the malar implant 140 andthe underlying bone once the malar implant 140 has been implanted.Alternatively, the width W1 can be constant across the entire malarimplant 140.

The body 142 can also include at least one registration feature that isconfigured to align with or abut complementary landmark features of thefacial skeleton. The registration feature can be configured as a flange50 that extends out from the inner surface 146 or, as shown in theillustrated embodiment from the peripheral edge 148. For instance theflange can extend from the inner surface 146 or the peripheral edge 148substantially along a second direction, such as a direction ofelongation 149, which is perpendicular to the first direction 147. Theflange 50 can extend out from the inner surface 146 or the peripheraledge 148 a distance D1 along the direction of elongation 149. As shownin the illustrated embodiment, the body can further include a secondflange 50 that is spaced from the at least one flange. The second flangeextends away from the peripheral edge along a third direction that isangularly offset with respect to the first direction, wherein the planefurther intersects the second flange. In one embodiment the plane isoriented substantially perpendicular to the third direction. In anotherembodiment, the third direction is substantially normal to the plane.The third direction can be parallel to the second direction, or thethird direction can be angularly offset with respect to the seconddirection, for instance such that the second and third directionsconverge.

The flange 50 can include an abutment surface 152 and an opposedexterior surface 154. The flange 50 defines a width W2 that can bedefined between the abutment surface 152 and the exterior surface 154along the first direction 147. The width W2 of the flange 50 can be thesame as the width W1 of the malar implant 140 at the position where theflange 50 extends out from the body 142. Alternatively, the width W2 ofthe flange 50 can be different than the width W1 of the malar implant140, such that the width W2 of the flange 50 is either greater than orless than the width W1 of the malar implant 140 where the flange 50extends out from the body 142. The abutment surface 152 can be contouredto correspond to a landmark feature of the facial skeleton. Thedescription of the flange 50 as described in regards to FIGS. 18A-18D isapplicable to the registration features and flanges 50 referred to inthe other embodiments within the present disclosure.

The flange 50 can be angularly offset with respect to the inner surface146 and substantially rigidly positioned such that the abutment surface152 of the flange 50 is configured to abut the complementary landmarkfeature of the underlying malar bone so as to prevent movement of theimplant 140 relative to the underlying malar in at least one directionwhen the implant 140 is positioned adjacent the underlying malar. Forexample, the abutment surface 152 can be configured to abut a landmarkfeature of the underlying malar such that movement of the implant 140 inone direction along a superior-inferior axis is prevented when theimplant 140 is positioned adjacent the underlying malar bone. It canfurther be said that the flange 50 can be angularly offset to the innersurface 146 and positioned such that the flange 50 is configured to abuta landmark feature of the underlying malar bone such that movement ofthe implant 140 in a direction parallel to the inner surface 146 isprevented when the inner surface 146 is positioned adjacent theunderlying malar bone.

In one embodiment, the flange 50 can be angularly offset to the innersurface 146 and positioned such that the abutment surface 152 of theflange 50 abuts an underlying malar bone such that movement of the malarimplant 140 in a direction parallel to the inner surface 146 isprevented when the inner surface 146 is positioned adjacent theunderlying malar bone. The flange 50 can extend substantiallyperpendicular to the inner surface 148 or alternatively, the flange 50can extend at any other angle from the inner surface 148. As shown theflange 50 can extend out from the peripheral edge 148. Alternatively,the flange 50 can extend out from the body 142 at a position eitherspaced apart from or adjacent to the peripheral edge 148 of the malarimplant 140. The flange 50 can be positioned such that the abutmentsurface 152 will abut a landmark feature of the underlying cheek bonewhen the malar implant is positioned adjacent the malar bone. Thelandmark feature of the underlying malar bone can include, but is notlimited to: a zygomatic arch; a lateral infraorbital rim; and othercraniofacial bones. The malar implant 140 can include more than oneflange 50 positioned such that each of the flanges 50 will abut eitherthe same or a different landmark feature of the underlying bone. Forexample, in one embodiment the malar implant 140 can include first andsecond flanges 50 positioned such that when the malar implant isimplanted adjacent an underlying malar bone, the abutment surface 152 ofthe first flange 50 abuts an underlying zygomatic arch and the abutmentsurface 152 of the second flange 50 abuts an underlying lateralinfraorbital rim such that movement of the of the malar implant 140 in adirection parallel to the inner surface 146 is prevented.

In accordance with one embodiment, the craniofacial implant 140 isconfigured to be implanted between a honey structure and soft tissue.The implant 140 includes [[an inner contoured surface 146 that isadapted to conform to the underlying malar bone when the malar implant140 is implanted between the boney structure and the soft tissue. Theimplant can further include an outer contoured surface 144 that isadapted to underlie the soft tissue when the implant is implantedbetween the boney structure and the soft tissue, and a peripheral edge148 disposed between the inner contoured surface 146 and the outercontoured surface 144. The implant 140 can further include at least oneflange 50 disposed along and extending from at least a portion of theperipheral edge 148. Each of the at least one flange 50 can bepositioned and adapted so as to abut a landmark feature of theunderlying malar when the malar implant 140 is implanted between theboney structure and the soft tissue such that abutment between theflange 50 and the landmark feature prevents movement of the malarimplant 140 in a direction parallel to the inner contoured surface. Themalar implant 140 can further define a line 160 that extends from theperipheral edge 148 at a first location 162 to the peripheral edge 148at a second location 164, the line intersecting with the at least oneflange 50 and the at least one flange 50 extends along the direction ofelongation 149 and the line 160 is substantially perpendicular to thedirection of elongation 149.

Furthermore, as described above, the inner surface 146 can be curvedwith a concavity 155. In accordance with the illustrated embodiment, theconcavity 155 can be partially bound by the flange 50. Additionally, theinner surface 146 can be concave with respect to a plane P1 that can beoriented such that one side of the plane P1 faces the concavity 155,extends through at least a select one or more of the flanges 50, and issubstantially perpendicular to the direction of elongation 149 of theselect one or more of the flanges 50. Additionally still, the body 142can define a plane P2 that contacts the peripheral edge 148 at three ormore locations on the peripheral edge 148, such as a first location 170,a second location 172 and a third location 174, the plane P2 intersectsa select one or more of the flanges 50, and is angularly offset, forinstance substantially perpendicular, with respect to the direction ofelongation 149 of the select one or more of the flanges 50.

In one embodiment, proper positioning of the malar implant 140 can beverified, for example the flange 50 is abutting the zygomatic arch (orother landmark feature of the underlying malar), through an incisionjust lateral to the lateral canthus (referred to as a “crow's feetincision”). Once the malar implant 140 has been inserted and positionedas desired, a portion of the malar implant 140 may overlie with aninferior aspect of an orbital rim of the underlying bone structure. Thisoverlying portion of the malar implant 140 can be extended superiorlytoward the level of the canthus. A fixation device, for instance ascrew, could then be passed through the extended portion to secure themalar implant 140 in a desired position. In one embodiment, the extendedportion can be thin with no flange 50.

While there have been depicted and described various embodiments,dimensions, and materials of the various embodiments and aspects of theinvention, unless otherwise stated these are exemplary in nature and thescope of the invention is not limited thereto.

The embodiments described in connection with the illustrated embodimentshave been presented by way of illustration, and the present invention istherefore not intended to be limited to the disclosed embodiments.Furthermore, the structure and features of each the embodimentsdescribed above can be applied to the other embodiments describedherein, unless otherwise indicated. Accordingly, those skilled in theart will realize that the invention is intended to encompass allmodifications and alternative arrangements included within the spiritand scope of the invention, for instance as set forth by the appendedclaims.

What is claimed:
 1. A craniofacial implant comprising: a first bodyportion and a second body portion wherein the first and second bodyportions comprise separate segments, wherein each of the first andsecond body portions defines a bone facing inner surface and an opposedouter surface, wherein the first and second body portions aresubstantially symmetrical, wherein each of the first and second bodyportions is shaped to correspond to respective portions of a mandible;and wherein the bone facing inner surface and the opposed outer surfaceof each of the first and second body portions extends along a firstdirection adjacent to a peripheral edge of the body portion; a joiningelement configured to attach the separate segments comprising the firstand second body portions to each other; and a flange substantiallyrigidly positioned to extend from at least one of the first or secondbody portion wherein the flange extends away from the peripheral edge ofthe first or second body portion along a second direction that isangularly offset with respect to the first direction, the flange havingan abutment surface positioned to abut a landmark bone feature of themandible so as to prevent movement of the implant relative to themandible in at least one direction when the implant is positionedadjacent the mandible.
 2. The craniofacial implant as recited in claim1, wherein the inner bone facing surface and the opposed outer surfaceare spaced apart from each other along a first direction, and the flangeextends from the inner bone facing surface of the first body portionalong the first direction.
 3. The craniofacial implant as recited inclaim 2, wherein the flange extends from the inner bone facing surfacealong a direction from the outer surface toward the inner surface. 4.The craniofacial implant as recited in claim 1, wherein at least one ofthe first and second body portions defines a recess that is sized andconfigured to receive a portion of the joining element.
 5. Thecraniofacial implant as recited in claim 1, wherein the joining elementis integral with one of the first and second body portions.
 6. Thecraniofacial implant as recited in claim 1, wherein the flange ispositioned to abut an inferior border of the mandible so as to preventmovement of the implant relative to the mandible in at least onedirection when the implant is positioned adjacent the mandible.
 7. Thecraniofacial implant as recited in claim 1, wherein the abutment surfaceis contoured to correspond to a complementary contour of the landmarkbone feature.
 8. The craniofacial implant as recited in claim 1, whereinthe at least one direction is parallel to the inner surface of the bodyportion that the flange extends from.
 9. The craniofacial implant asrecited in claim 1, wherein the first body portion further comprises asuperior edge and an inferior edge, the superior edge and the inferioredge each extending between the inner and outer surfaces of the firstbody portion.
 10. The craniofacial implant as recited in claim 9,wherein at least a portion of the first superior edge and the firstinferior edge are tapered.
 11. The craniofacial implant as recited inclaim 9, wherein the first body portion defines an anterior end and aposterior end, such that both the inner and outer surfaces and theinferior and superior edges extend between the anterior and posteriorends substantially along a central aide axis, and at least one of theanterior and posterior edges is tapered toward the other of the anteriorand posterior edges along a direction from the anterior end toward theposterior end.
 12. The craniofacial implant as recited in claim 9,wherein the central axis extends between the anterior and posteriorends, and the central axis is curved.
 13. A craniofacial implantcomprising: a body having an inner contoured surface that is at leastpartially concave and that is adapted to conform to a boney structure,an opposed outer surface adapted to underlie soft tissue and spacedapart from the inner contoured surface, and a peripheral edge extendingbetween the inner contoured surface and the outer surface wherein theinner contoured surface and the outer surface extend along a firstdirection adjacent to the peripheral edge extending between the innercontoured surface and the outer surface; and at least one flangesubstantially rigidly positioned to extend from a portion of theperipheral edge and away from the peripheral edge along a seconddirection that is substantially perpendicular to the first directionalong which the inner contoured surface and the outer surface extendadjacent to the peripheral edge, the at least one flange positioned toabut a landmark feature of the boney structure such that movement of theimplant in a direction parallel to the inner contoured surface isprevented when the inner contoured surface is positioned adjacent theboney structure.
 14. The craniofacial implant as recited in claim 13,wherein the landmark feature comprises a zygomatic arch or a lateralinfraorbital rim.
 15. The craniofacial implant as recited in claim 13,wherein the distance between the inner contoured surface and the outercontoured surface measured in the first direction defines a first width.16. The craniofacial implant as recited in claim 15, wherein each of theat least one flange comprises an abutment surface configured to abut thelandmark feature and an opposed exterior surface, the distance betweenthe abutment surface and the exterior surface measured in the firstdirection defines a second width.
 17. The craniofacial implant asrecited in claim 16, wherein the first width is greater than the secondwidth at the portion of the peripheral edge.
 18. The craniofacialimplant as recited in claim 16, wherein the abutment surface iscontoured to correspond to a landmark feature of the boney structure.19. The craniofacial implant as recited in claim 13, further comprisinga second flange that is spaced from the at least one flange and whereinthe second flange is substantially rigidly positioned to extend awayfrom the peripheral edge along a third direction that is angularlyoffset with respect to the first direction.
 20. A craniofacial implantcomprising: a body having an inner surface that is at least partiallyconcave and that is adapted to conform to a boney structure, an opposedouter surface adapted to underlie soft tissue and spaced apart from theinner surface, and a peripheral edge extending between the inner surfaceand the outer surface wherein the inner contoured surface and the outersurface extend along a first direction adjacent to the peripheral edgeextending between the inner contoured surface and the outer surface; andat least one flange substantially rigidly positioned to extend away fromthe peripheral edge along a second direction that is angularly offsetwith respect to the first direction along which the inner contouredsurface and the outer surface extend adjacent to the peripheral edge,wherein the at least one flange is positioned to abut a landmark featureof the boney structure when the inner contoured surface is positionedagainst the boney structure.
 21. The craniofacial implant as recited inclaim 20, wherein the second direction is substantially perpendicular tothe first direction.
 22. The craniofacial implant as recited in claim20, further comprising a second flange that is spaced from the at leastone flange and wherein the second flange is substantially rigidlypositioned to extend away from the peripheral edge along a thirddirection that is angularly offset with respect to the first direction.